1. Field of the Invention
This invention pertains generally to aeronautic and astronautic craft structure and more particularly to doors.
2. Related Art
Human beings have taken to the skies and outer space in aeronautic and astronautic crafts. These crafts encounter a lowering of atmospheric pressure and breathable air for human occupants as altitude increases. Ultimately, in outer space, there is a near perfect vacuum with virtually no atmospheric pressure and no breathable air.
Aeronautic and astronautic crafts can be designed to adapt to this lowering of atmospheric pressure with an arrangement that seals the internal space of the craft from the external environment and that creates an internal pressure greater than the external pressure. With a sufficient internal pressure, there is breathable air for human occupants. Accordingly, aeronautic and astronautic crafts are generically referred to as pressure vessels. A pressure vessel has a finite and limited internal volume.
Pressure vessels have a lift system that overcomes the force of gravity. This lift system typically is powered by an internal combustion engine, turboprop engine, jet engine, rocket engine, buoyancy of a hot air balloon or buoyancy of a helium balloon. The lift system has a finite and limited lift capability. This finite and limited lift capability in turn imposes a maximum weight capacity for the pressure vessel.
Pressure vessels have one or more doors that open and close so that human occupants (and things) can enter and leave the pressure vessel. Typically, these doors have hinges, latches, locking devices and other hardware. The door related hardware disadvantageously adds weight to the pressure vessel which must be overcome by the lift system. Accordingly, the weight of door hardware competes for an allocation of weight capacity with equipment, instrumentation, cargo and/or occupants being on board the pressure vessel.
The door requires a free area within the pressure vessel for operation; typically, a free area in which to swing in and out. This free area for operation disadvantageous competes for an allocation of internal volume with equipment, instrumentation, cargo and/or occupants being on board the pressure vessel.
United States Patent Publication US2004/0262314 A1 by Weatherhead et al. teaches a hatch cover apparatus for a container. The hatch cover apparatus is comprised of a lid adapted to cover an opening. The lid is mounted to collars that slidingly run along parallel cylinder rails. The apparatus includes an expandable seal positioned between the lid and the container and an arrangement for retaining the cover lid in a closed position when the seal is expanded. This apparatus has the disadvantage of added weight from the hardware that makes up the sliding and retaining arrangement. The apparatus has the disadvantages of an expandable seal which adds complexity and risk of failure. The hatch cover apparatus is not aerodynamic and poorly suited for pressure vessels.
United States Patent Publication US2006/0086735 A1 by Weerth teaches a spherical blast resistant container. The container has a non-circular (e.g., elliptical) doorway opening and an oversized hatch. The oversized hatch is fitted on an angle through the doorway opening. The hatch is manipulated parallel to the doorway opening. The container becomes pressurized by an explosive detonation. When this occurs, the greater surface area of the hatch presses against the inside surface of the container wall so as to seal the container. This patent publication has the shortcoming of not teaching a system for laterally translocating the hatch from an open doorway to a closed doorway. It has the disadvantage of requiring the hatch to be a non-circular shape which impedes laterally translocating the hatch.
U.S. Pat. No. 4,277,855 by Poss teaches a skylight that moves radially from a closed to open position for ventilation. The skylight is comprised of a dome that is mounted to a sleeve that is received in an opening in a curved wall. The sleeve slides radially within the opening to lift the skylight dome to an upper ventilating position. The dome lowers to engage a weather stripping within a recess. This skylight system is not a door with the utility of an opening through which human occupants (and things) can enter and leave.
There is a need for a pressure vessel door system which reduces and/or eliminates the addition of weight to the pressure vessel by hinges, latches, locking devices and/or other hardware. There exists a need for a pressure vessel door system that is lightweight compared to the state of the art.
There is a need for a pressure vessel door system which does not take-up internal volume for swing-in and swing-out. There is a need for a pressure vessel door system that has a small operational volume compared to the state of the art.
There is a need for a pressure vessel door system that satisfies the above needs for limited weight and operational space where the door is not left free and unsupported to be lifted and removed in and out place.
There is a need for a pressure vessel door system that satisfies the above needs for limited weight and operational space where opening and closing/sealing the door is not time consuming.
There is a need for a pressure vessel door system that satisfies the above needs for limited weight and operational space which is simple to construct, operate and maintain.
There is a need for a pressure vessel door system that satisfies the above needs for limited weight and operational space which is inexpensive to construct, operate and maintain.
There is a need for a pressure vessel door system that satisfies the above needs for limited weight and operational space which is strong, tough, resistant to rupture, resistant to strain and resistant to failure.
The present invention satisfies these needs, as well as others, and generally overcomes the presently known deficiencies in the art.